Vulcan also considers a 90 degree offset in the bearing as a consequence of labeling the X axis as the principal axis. For example, Vulcan considers the X axis to be the major axis, and the Euler angles rotate about the ZYX axes, with positive clockwise bearing, positive upwards plunge and a positive upwards dip. In some cases it may be simple to convert between conventions. Given the three different axes to rotate about, and the dozens of possible sequences, along with the different sign conventions, and even different principal axes, it can be difficult to convert between formats accurately. This is not the only convention out there. GSLIB considers the Y axis as the principal axis and the Euler angles rotate about the ZXY axes, with positive clockwise, positive upwards, and positive downwards. \left[ \begin = R^T\) which means that rotations may be reversed very easily by simply multiplying by the transpose.
Which may be expressed in matrix notation as When orienting a new coordinate system any point \((x, y)\) may be transformed into a rotated point \((x', y')\) using the following equations: This angle is measured positive clockwise from the Y axis (North). In geologic modeling we generally consider the azimuth, or bearing, which is denoted \(\alpha\). A single angle may be used to describe the rotation. Orienting an object or coordinate system is substantially easier in 2D than in 3D. The underlying principles explained here will also allow for modelers to transform between different conventions. This lesson will use and explain the conventions behind the GSLIB (Deutsch & Journel, 1998). This lesson will explain how the most common kinds of parameters operate, and the mathematics behind them so that geologic modelers can efficiently and accurately specify orientations. Correctly orienting objects in 3D is a difficult task, due primarily to cryptic parameters and many different conventions. Experimental variograms are calculated in particular directions of interest, search ellipsoids for kriging and simulation are oriented along directions of geologic continuity, and even the underlying coordinate system may be re-oriented for modeling efficiency. When performing geologic modeling it is necessary to orient anisotropy in three dimensional space.
The Angle Specification for GSLIB Software Matthew Deutsch The Angle Specification for GSLIB Software. This course if for geologists, mining engineers, geoscientists or anyone who wants to learn a new mining package.Cite this lesson as: Deutsch, M.
Upon the request of students more lectures will be added to this course based on their need, i m also planning on adding a full mine design section to this course to make it the only surpac course you will need to get started with the software. An introduction to block modelling in surpac is also included and this section will be updated soon with more videos that covers the ressource estimation process.
This course will cover the basics of modelling in surpac, we will start with creating a geological database and the cover how to create solid ore body using the explicit method. Surpac is also a CAD tool that offers some advanced features for mine design ( open pit and underground). With this powerful mining package geologists can create geological databases and model ore bodies using explicit modelling method the ore body solid is used later to constraint a block model and do ressource estimation. Geovia Surpac is one the most used software in the mining industry, it allows mining engineers and geologist to perform alot of tasks in different levels in the life of a mine.